The present invention relates to a rotary type fluid machine and a vane type fluid machine which can also be used as an expanding machine and/or a compressing machine, and a waste heat recovering device for an internal combustion engine for extracting mechanical energy utilizing waste heat of the internal combustion engine.
Japanese Patent Application Laid-open No. 6-88523 describes a waste heat recovering device for an internal combustion engine for generating high temperature and high pressure vapor with heat energy of exhaust gas of the internal combustion engine and supplying the high temperature and high pressure vapor to a turbine type expanding machine to generate mechanical energy.
Japanese Patent Application Laid-open No. 59-41602 describes a double multi-vane type rotary machine. This is such that a circular vane support ring is disposed between an oval outer cam ring and an oval inner cam ring, and that outer ends and inner ends of a plurality of vanes supported slidably in radial directions by the vane support ring are placed in abutment against an inner peripheral surface of the outer cam ring and an outer peripheral surface of the inner cam ring, respectively. Thus, when the vane support ring exerts a relative rotation with respect to the outer cam ring and inner cam ring, volume of a plurality of operation chambers comparted by the vanes between the outer cam ring and the vane support ring is expanded or compressed to function as an expanding machine or a compressing machine, and volume of a plurality of operation chambers comparted by the vanes between the inner cam ring and the vane support ring is expanded or compressed to function as an expanding machine or a compressing machine.
In this double multi-vane type rotary machine, outer and inner rotary machines can be used as respectively independent expanding machines, the outer and inner rotary machines can be used as respectively independent compressing machines, or one and the other of the outer and inner rotary machines can be respectively used as the expanding machine and compressing machine.
Japanese Patent Application Laid-open No. 60-206990 describes a vane type rotary machine which can be used as an expanding machine or a compressing machine. This is such that a circular intermediate cylinder is disposed in an offset manner between a circular outer cam ring and a circular inner cam ring, which are disposed concentrically, and that outer ends and inner ends of a plurality of vanes supported slidably in the radial directions by the intermediate cylinder are placed in abutment against an inner peripheral surface of the outer cam ring and an outer peripheral surface of the inner cam ring, respectively. Thus, when the intermediate cylinder exerts a relative rotation with respect to the outer cam ring and inner cam ring, volume of a plurality of operation chambers comparted by the vanes between the outer cam ring and the vane support ring is expanded or compressed to function as an expanding machine or a compressing machine, and volume of a plurality of operation chambers comparted by the vanes between the inner cam ring and the vane support ring is expanded or compressed to function as an expanding machine or a compressing machine.
In this vane type rotary machine, outer and inner rotary machines can be used as respectively independent expanding machines, the outer and inner rotary machines can be used as respectively independent compressing machines, or a working fluid having passed through one of the outer and inner rotary machines can be made to pass through the other to connect the outer and inner rotary machines in series for operation as a two-stage expanding machine or a two-stage compressing machine.
Japanese Patent Application Laid-open No. 57-16293 describes a vane type rotary compressor. This is such that a circular rotor is rotatably disposed in a non-circular cam ring, and that a roller provided at an intermediate portion of each vane is guided in engagement with a roller track provided in a casing in such a manner that tips of a plurality of vanes radially supported by the rotor move along an inner peripheral surface of the cam ring.
Japanese Patent Application Laid-open No. 64-29676 describes a radial plunger pump. This is such that a plurality of cylinders are radially formed in a rotor disposed in an offset manner in a circular cam ring, and that tips of plungers slidably fitted to the cylinders are placed in abutment against an inner peripheral surface of the cam ring to be reciprocated and thereby operated as a pump.
Japanese Patent Application Laid-open No. 58-48706 describes a Rankine cycle apparatus comprising a vane type expanding machine. This is such that high temperature and high pressure vapor energy generated by an evaporating machine using a gas burner as a heat source is converted to mechanical energy via a vane type expanding machine, and that resultant reduced temperature and reduced pressure vapor is condensed by a condensing machine and then returned again to the evaporating machine by a supply pump.
The applicant proposes a waste heat recovering device for an internal combustion engine having an evaporating machine for generating high temperature and high pressure vapor using waste heat as a heat source, an expanding machine for generating an output by expansion of the high temperature and high pressure vapor, and a condensing machine for liquefying reduced temperature and reduced pressure vapor exhausted from the expanding machine, in order to recover waste heat of the internal combustion engine.
The above-described expanding machine proposed by the applicant is such that a piston is slidably fitted to a cylinder radially formed in a rotor, and that high temperature and high pressure vapor is successively supplied from a fixed shaft disposed at the center of the rotor to each cylinder to drive the piston and thereby rotate the rotor. A rotary valve for supplying high temperature and high pressure vapor from the inside of the hollow fixed shaft to each cylinder with predetermined timing is such that a seal block made of carbon for guiding the high temperature and high pressure vapor is resiliently in sliding contact with an inner peripheral surface of the hollow shaft formed with a through-hole communicating with the cylinder, and that the spring force is generated by a spring and a bellows operated by the high temperature and high pressure vapor.
It should be noted here that the expanding machine disclosed in the Japanese Patent Application Laid-open No. 6-88523 is the turbine type expanding machine of the non-displacement type, but known as a displacement type expanding machine are a piston type expanding machine and a vane type expanding machine.
Each of the machines disclosed in the Japanese Patent Application Laid-open No. 59-41602 and the Japanese Patent Application Laid-open No. 60-206990 comprises the plurality of vane type rotary machines disposed inside and outside in the radial directions, and the vane type rotary machine has a simple structure of a conversion mechanism between pressure energy and mechanical energy and can deal with a large flow amount of working fluid with a compact structure, while there is a problem that a large leak amount of the working fluid from a slide portion of the vane makes it difficult to increase efficiency.
The radial plunger pump described in the Japanese Patent Application Laid-open No. 64-29676 has high sealing performance of a working fluid because the working fluid is compressed by a piston slidably fitted to the cylinder, and can minimize an efficiency reduction due to a leak even when using a high pressure working fluid, while there is a problem of requiring a crank mechanism or slanting mechanism for converting reciprocating motion of the piston into rotary motion, which makes the structure complex.
Therefore, it is desirable to make a rotary type fluid machine, vane type fluid machine, or waste heat recovering device for an internal combustion engine have both merits belonging to the piston type and merits belonging to the vane type. Further, in the vane type. fluid machine or waste heat recovering device for the internal combustion engine, it is desirable to minimize a leak amount of a working fluid from a slide portion of a vane.
In the above-described expanding machine proposed by the applicant, the high temperature and high pressure vapor in the cylinder on the rotor is sometimes condensed to be liquefied at the time of actuation when the temperature is not sufficiently raised, and moreover, there is also a possibility that water used as a lubricating medium may permeate the cylinder. When the piston is moved in the cylinder in a state where the water is thus trapped in the cylinder, there is a possibility that normal operation of the cylinder and piston may be inhibited, and hence, the water trapped in the cylinder is required to be rapidly exhausted outwards.
The above-described expanding machine proposed by the applicant requires not only the seal block made of carbon but also the spring or bellows for pressing the same against the inner peripheral surface of the hollow shaft, thus there is a problem of complexity of a structure which increases the number of components. Further, difference in coefficient of thermal expansion between the seal block made of carbon and the hollow shaft of SUS-based metal causes a radial distortion at the time of high temperature, and there is a possibility of a leak of part of the high temperature and high pressure vapor without contribution to driving of the rotor.
A first object of the present invention is to make a rotary type fluid machine, a vane type fluid machine, or a waste heat recovering device for an internal combustion engine have both merits belonging to the piston type and merits belonging to the vane type.
A second object of the present invention is to greatly increase sealing performance between a rotor chamber and a vane in a vane type fluid machine or a waste heat recovering device for an internal combustion engine.
A third object of the present invention is, in a rotary type fluid machine, to prevent water condensed in a cylinder at the time of actuation or the like when temperature is low or water supplied as a lubricating medium from being trapped in the cylinder.
A fourth object of the present invention is to reliably prevent a leak of a high pressure fluid from a rotary valve of a rotary type fluid machine with a simple structure including a reduced number of components.
To achieve the first object, according to a first feature of the present invention, there is proposed a rotary type fluid machine having an expanding function and a compressing function, including a casing having a rotor chamber, a rotor accommodated in the rotor chamber, and a plurality of vane-piston units which are radially disposed in the rotor around a rotary axis thereof and freely reciprocated in the respective radial directions, each of the vane-piston units having a vane sliding in the rotor chamber and a piston placed in abutment against a non-slide side of the vane, wherein when functioning as an expanding machine, expansion of a high pressure fluid is used to operate the piston to rotate the rotor via a power conversion device and expansion of a low pressure fluid caused by a pressure reduction in the high pressure fluid is used to rotate the rotor via the vane, while when functioning as a compressing machine, rotation of the rotor is used to supply a low pressure fluid to the side of the piston via the vane and the piston is operated by the vane to convert the low pressure fluid to a high pressure fluid.
With the above first feature, the rotary type fluid machine having the expanding function and compressing function can be provided, wherein the piston is allowed for works on a high pressure side to achieve efficiency improvement by restraining leak loss, while the vane is allowed for works on a low pressure side to efficiently deal with a large amount of flow.
To achieve the second object, according to a second feature of the present invention, there is proposed a vane type fluid machine, including a casing having a rotor chamber, a rotor accommodated in the rotor chamber, and a plurality of vanes which are radially disposed in the rotor around a rotary axis thereof and freely reciprocated in the respective radial directions, wherein a section of the rotor chamber in a phantom plane including the rotary axis of the rotor is formed of a pair of semi-circular sections with diameters thereof opposed to each other and a rectangular section formed by connecting opposed one ends of both the diameters to each other and opposed other ends of the diameters to each other, respectively, each of the vanes includes a vane body and a seal member mounted to the vane body and pressed against the rotor chamber with a spring force, and the seal member has a semi-circular arcuate portion sliding on the inner peripheral surface defined by the semi-circular section of the rotor chamber and a pair of parallel portions respectively sliding on opposed inner end surfaces defined by the rectangular section.
With the above second feature, the vane type fluid machine which has greatly increased sealing performance between the rotor chamber and the vane can be provided.
To achieve the first object, according to a third feature of the present invention, there is provided a waste heat recovering device for an internal combustion engine having an evaporating machine using waste heat from the internal combustion engine as a heat source to generate high pressure vapor, an expanding machine for generating an output by expansion of the high pressure vapor, and a condensing machine for liquefying low pressure vapor exhausted from the expanding machine, characterized in that the expanding machine includes a casing having a rotor chamber, a rotor accommodated in the rotor chamber, and a plurality of vane-piston units which are radially disposed in the rotor around a rotary axis thereof and freely reciprocated in the respective radial directions, each of the vane-piston units including a vane sliding in the rotor chamber and a piston placed in abutment against a non-slide side of the vane, expansion of the high pressure vapor being used to operate the piston to rotate the rotor via the vane, and expansion of a low pressure gas caused by a pressure reduction in the high pressure gas being used to rotate the rotor via the vane.
With the above third feature, in the expanding machine, when the piston is allowed for works on a high pressure side as described above, efficiency can be increased by restraining leak loss, while when the vane is allowed for works on a low pressure side, a large amount of flow can be efficiently dealt with. This permits extracting a high output from the waste heat of the internal combustion engine.
To achieve the second object, according to a fourth feature of the present invention, there is proposed a waste heat recovering device for an internal combustion engine having an evaporating machine using waste heat from the internal combustion engine as a heat source to generate high pressure vapor, an expanding machine for generating an output by expansion of the high pressure vapor, and a condensing machine for liquefying low pressure vapor exhausted from the expanding machine, characterized in that the expanding machine includes a casing having a rotor chamber, a rotor accommodated in the rotor chamber, and a plurality of vanes which are radially disposed in the rotor around a rotary axis thereof and freely reciprocated in the respective radial directions, a section of the rotor chamber in a phantom plane including the rotary axis of the rotor being formed of a pair of semi-circular sections with diameters thereof opposed to each other and a rectangular section formed by connecting opposed one ends of both the diameters to each other and opposed other ends of the diameters to each other, respectively, each of the vanes including a vane body and a seal member mounted to the vane body and pressed against the rotor chamber with a spring force, and the seal member having a semi-circular arcuate portion sliding on the inner peripheral surface defined by the semi-circular section of the rotor chamber and a pair of parallel portions respectively sliding on opposed inner end surfaces defined by the rectangular section.
With the above fourth feature, in the vane type expanding machine, sealing performance between the rotor chamber and the vane can be sufficiently increased to greatly improve efficiency under a high pressure.
To achieve the third object, according to a fifth feature of the present invention, there is proposed a rotary type fluid machine having an expanding function and a compressing function including a casing having a rotor chamber, a rotor accommodated in the rotor chamber, and a plurality of vane-piston units which are radially disposed in the rotor around a rotary axis thereof and freely reciprocated in the respective radial directions, each of the vane-piston units including a vane sliding in the rotor chamber and a piston placed in abutment against a non-slide side of the vane, and when functioning as an expanding machine, expansion of a high pressure fluid being used to operate the piston to rotate the rotor via a power conversion device and expansion of a low pressure fluid caused by a pressure reduction in the high pressure fluid being used to rotate the rotor via the vane, while when functioning as a compressing machine, rotation of the rotor being used to supply a low pressure fluid to the side of the piston via the vane and the piston being operated by the vane to convert the low pressure fluid to a high pressure fluid, characterized in that the rotary type fluid machine includes fluid exhausting means for maintaining airtight between the piston and cylinder during a stroke of the piston sliding in the cylinder formed in the rotor, and for exhausting a fluid stored in the cylinder at a stroke end of the piston outside the cylinder.
With the above fifth feature, even when water used as a lubricating medium permeates the cylinder or even when the high temperature and high pressure vapor in the cylinder of the rotor is condensed to be liquefied at the time of low temperature actuation or the like of the rotary type fluid machine which functions as the expanding machine, water trapped in the cylinder can be rapidly exhausted outward at the stroke end of the piston by the fluid exhausting means and inhibition of normal operation of the piston in the cylinder can reliably be prevented.
To achieve the fourth object, according to a sixth feature of the present invention, there is proposed a rotary type fluid machine having an expanding function and a compressing function, including a casing having a rotor chamber, a rotor accommodated in the rotor chamber, and a plurality of vane-piston units which are radially disposed in the rotor around a rotary axis thereof and freely reciprocated in the respective radial directions, each of the vane-piston units including a vane sliding in the rotor chamber and a piston placed in abutment against a non-slide side of the vane, when functioning as an expanding machine, expansion of a high pressure fluid being used to operate the piston to rotate the rotor via a power conversion device and expansion of a low pressure fluid caused by a pressure reduction in the high pressure fluid being used to rotate the rotor via the vane, while when functioning as a compressing machine, rotation of the rotor being used to supply a low pressure fluid to the side of the piston via the vane and the piston being operated by the vane to convert the low pressure fluid to a high pressure fluid, characterized in that first passages for supplying and exhausting a high pressure fluid to a cylinder formed in the rotor and second passages for supplying and exhausting a low pressure fluid from the cylinder to a rotor chamber are formed in a fixed shaft, and that a switchover mechanism which is rotated integrally with the rotor to selectively connect the first passages or the second passages to the cylinder is fitted rotatably and in a sealing condition-relative to the fixed shaft.
According to the sixth feature, a switchover mechanism which is rotated integrally with the rotor to selectively communicate the first passages or the second passages to the cylinder is fitted rotatably and in a sealing condition relative to the fixed shaft. Therefore, a leak of the high pressure fluid can reliably be prevented with a simple structure including a reduced number of components, requiring no special urging means such as a spring or bellows, simply by controlling clearance between the fixed shaft and switchover mechanism.
To achieve the fourth object, according to a seventh feature of the present invention, there is proposed a rotary type fluid machine having an expanding function and a compressing function, including a casing having a rotor chamber, a rotor accommodated in the rotor chamber, and a plurality of vane-piston units which are radially disposed in the rotor around a rotary axis thereof and freely reciprocated in the respective radial directions, each of the vane-piston units including a vane sliding in the rotor chamber and a piston placed in abutment against a non-slide side of the vane, when functioning as an expanding machine, expansion of a high pressure fluid being used to operate the piston to rotate the rotor via a power conversion device and expansion of a low pressure fluid caused by a pressure reduction in the high pressure fluid being used to rotate the rotor via the vane, while when functioning as a compressing machine, rotation of the rotor being used to supply a low pressure fluid to the side of the piston via the vane and the piston being operated by the vane to convert the low pressure fluid to a high pressure fluid, characterized in that first passages for supplying and exhausting a high pressure fluid to a cylinder formed in the rotor and second passages for supplying and exhausting a low pressure fluid from the cylinder to a rotor chamber are formed in a fixed shaft, that a switchover mechanism which is rotated integrally with the rotor to selectively communicate the first passages or the second passages to the cylinder is fitted rotatably and in a sealing condition relative to the fixed shaft, and that port grooves surrounding outer peripheries of the first passages are formed on a slide surface between the fixed shaft and switchover mechanism.
With the above seventh feature, a switchover mechanism which is rotated integrally with the rotor to selectively communicate the first passages or the second passages to the cylinder is fitted rotatably and in a sealing condition relative to the fixed shaft, and the port grooves surrounding the outer peripheries of the first passages are formed on a slide surface between the fixed shaft and the switchover mechanism. Therefore, even when the high pressure fluid supplied from the first passages is leaked without flowing into the cylinder via the switchover mechanism, or even when the high pressure fluid compressed by the piston is leaked without being supplied to the first passages, the high pressure fluid can be captured by the port grooves to minimize an outward leak, thus when using the rotary type fluid machine as the expanding machine, improvement in output performance can be achieved, and when using the rotary type fluid machine as the compressing machine, improvement in compressing performance can be achieved.